The issue I have with esims is I brought one back in 2022 that had calls, texts and data but I couldn't send texts so while O2 locally does seem be acceptable unless I can be assured that it was a one off I'm a tad wary about porting a number onto a esim and finding out that the issue reappears.
I must stress that the device at the time was the Motorola Moto G 5G which only supports esims via a adaptor you placed in the SIM card slot and activate via a app.
Setup was simple enough with calls and data working out the box it was just texts that didn't.
Other than that esims are a good idea, it's just I'm wary now of that issue reappearing.